This invention relates to a process for washing dishes in which a series of operations from washing of used dishes as carried in racks to loading of the racks with dishes to a wagon are carried out successively and automatically and to a system therefor.
Dishwashers which automatically wash large amounts of tableware such as dishes, teacups and glassware smeared after eating or drinking are installed mainly in the kitchens of coffee shops and restaurants and conveniently utilized for the business. To describe the basic structure of the dishwasher, for example, the dishwasher has a washing tank having an upper nozzle and a lower nozzle which rotate horizontally by the reactive force of jetting a cleaning fluid therefrom; a box-like casing which can cover the washing tank to define a washing chamber; and a pump for pressure-feeding the cleaning fluid to the nozzles, and a rack with dishes to be washed is designed to be accommodated in the washing chamber. The structure for introducing the rack into the washing chamber and removing it from the chamber after completion of washing is of:
(1) Door system, where a door is provided at the front side of the casing; or
(2) Lift system, where the washing chamber is covered with a casing having an open bottom, and the rack can be introduced into or removed from the chamber by descending or ascending the casing.
In both systems, the rack with dishes to be washed from which leavings have preliminarily been removed is introduced into the washing chamber, and then a high-temperature cleaning fluid is jetted from the upper and lower rotating nozzles against the dishes in the rack to effect main washing for a predetermined time, followed by rinsing by jetting hot water from the same nozzles against the dishes for a predetermined time to complete the entire process for washing dishes.
By the way, conventional dishwashers all require manual operations for introducing the rack with dishes to be washed into the dishwasher and removing the rack therefrom after completion of washing. Such manual operations may not cause many problems in coffee shops and restaurants of ordinary scale, but in the kitchens of hotels having large banquet rooms and of large-scale drive-in restaurants, such manual operations can be an unnegligible matter.
In other words, when a huge amount of dishes to be washed are brought about at one time in such large-scale restaurants, the operation of carrying racks in and out of the dishwasher is too heavy for one operator in view of the amount of work and the working time, and besides operation efficiency of the dishwasher is lowered, disadvantageously. In such case, two operators generally share the operation of carrying in the rack and the operation of carrying out the rack, but it requires additional personnel cost.
Under such circumstances, a continuous dish washing system for large-scale restaurants has been proposed, for example, as disclosed in Japanese Provisional Utility Model Publication No. 7970/1987, in which dishes to be washed are loaded on an endless belt conveyor, and the dishes are washed, as the belt is fed, by the shower jetted from the shower pipes disposed along the belt at an upper position and a lower position.
It is true that a large amount of dishes can be washed in such belt type dish washing system, but the dishes cannot be washed and rinsed well in this system since the washing is carried out only while the dishes pass under the shower zone. Further, the dish conveying belt must inevitably be elongated so as to carry out sufficient washing and rinsing of the dishes, requiring a long space in the kitchen.
Further, in the belt type dish washing system, an operator carries the washed dishes manually to a rack. However, the dishes may be soiled, since they cannot be carried without being touched by the operator.
On the other hand, dishwashers used in large-scale restaurants generally suffer the following disadvantages: In the kitchen of a large scale restaurant, racks with washed dishes are removed from the dishwasher one after another as the washing operation proceeds. These racks in many cases are loaded on the brackets of a wagon having castors and stored at a predetermined place. Accordingly, a heavy work is forced on an operator to load heavy racks full of dishes manually onto a wagon under the present circumstances. Besides, while rinsing of dishes is carried out by jetting hot water against the dishes at the final stage of washing to heat the dishes and racks to a high temperature, the operator may suffer burning when he carries out the racks immediately after rinsing.